I'd recommend you get some practice identifying and proving AI generated images. I agree this has a bit of that "look", but in this case I'm quite certain it's just repeated image compression/a cheap camera. Here's the major details I looked at after seeing your comment:

• The grass at the bottom left. AI is frequently sloppy with little details and straight lines, usually the ones in the background. In this case, you can look at any blade of grass and follow it, and its path makes sense. The same happens with the lines in the tiles, the water stains, etc.
• The birthmark on the large brown dog. In this case, this is a set of three photos, which gives us an easy way to spot AI. AI generated images start from random noise, so you'd never get the exact same birthmark, consistent across different angles, from a prompt like "large brown dog with white birthmark on chest". Spotting a change in the birthmark, or a detail like it, would be a dead giveaway, but I can't spot any.
• There are other tricks as well, such as looking for strange variations in contrast and exposure from the underlying noise, but those are more difficult to explain in text. Corridor Digital has some good videos demonstrating it with visual examples if you're interested, but suffice to say I don't pick up on that here either.

It's useful to be able to prove or disprove your suspicions, as well as to be able to back them up with something as simple as "this is AI generated, just look at the grass". Hope this helps!

I was able to find a post of this image daring back to 2023.

Doesn't mean it's not AI, just means it's a lot less likely.

Unlikely, just weird colour balance.

Nah, not shiny enough and the grass is too detailed for AI.